Bush chisel or hammer.



PATENTED SEPT. 11, 1906.

7 J. CAMPBELL. BUSH CHISEL 0R HAMMER.

APPLICATION ILILED MAB-5. 1906.

a'vwemtoz John Campbell JOHN CAMPBELL, OF KNOWLES, CALIFORNIA.

BUSH CHISEL OR HAMMER.

Specification of Letters Patent.

Patented Sept. 11, 1906.

Application filed March 5,1906. Serial N01 304,365.

To to whom it may concern/.-

Be it known that 1, JOHN CAMPBELL, a citizen of the United States, residing at Knowles, in the county of Madera and State of California, have invented certain new and useful Improvements in Bush Chisels or Hammers; and I do declare the following to be a full, clear, and exact description of the invention, such as will enable others skilled in the art to which it ap pertains to make and use the same.

My invention relates to improvements in stone-working devices, and more particularly to bush chisels or hammers for use in pneumatic stone-surfacing machines and the ike.

The object of the invention is to provide a simple and practical device of this character which will be exceedingly strong and durable and in which the cutting blades or plates Will not be weakened at the points where the fastening-bolts pass through them, so that there will be little danger of their breaking at these points, as frequently happens in the tools now in general use.

W'ith the above and other objects in view the invention consists of certain novel features of construct on, combination, and arrangement of parts hereinafter described and claimed.

In the accompanying drawings, Figure 1 is a perspective view of my improved bush.

chisel or hammer. Figs. 2 and 3 are vertical sectional views through the same, taken in planes at right angles to each other. Fig. 4 is a horizontal or transverse sectional view.

Referring to the drawings by numeral, 1 denotes my improved bush chisel or hammer, which consists of a head or body 2, having the usual reduced stem or shank 3 at its upper end and having detachably secured in its lower ends by means of bolts or the like, 4, a plurality of cutter plates or blades 5. The head 2, as shown, is of substantially rectangular form and has in its bottom a rectangular groove or channel 6 for the reception of the cutting-plates 5. Any number of the latter may be employed, and they may have bottom cutting edges 7 of any form and construction. Their upper edges are square to engage a removable gib 8, provided in the groove or channel 6, and in their side edges are formed alining semicircular shaped notches or recesses 9, through which the bolts 4 extend. The bolts 4 also pass through alining openings 10, formed in the integral ears or lugs 11, which are formed upon the ends of the depending sides 13 or arms of the head, which sides are formed by providing the groove or channel 6 in its bottom. Nuts 14 are secured upon the threaded ends of the bolt and against the outer face of one of the arms 13, the heads 15 of the bolts engaging the outer face of the other arm 13, as clearly shown in the drawings.

The construction, use, and advantages of the invention will be readily understood from the foregoing description, taken in connection with the accompanying drawings. It will be seen that by passing the bolts through the semicircular notches or recesses 9 in the side edges of the cutter-plates they Will not be weakened to any appreciable extent, and there will be little or no danger of them breaking across that portion, as frequently happens with the plates now in use, in which the fastening-bolts are passed through openings formed in the plates at some distance from their side edges and in the same transverse plane. Both the heads and the cutter-plates of tools of this character now in general use frequently break transversely along the line of their fastening-bolts because of the weakening of the parts by the location of the bolt-holes in the same transverse plane and adjacent to each other; but in my improved tool this danger is entirely avoided by reason of the arrangement of the bolts in the notches in the edges of the plates. The open ings 9 in the plates are somewhat larger in diameter than the bolts are in cross-section, so that all of the strain falls upon the gib 8 and the head 2 and not upon the bolts 4.

Having thus described my invention, what I claim as new, and desire to secure by Letters Patent, is

The herein-described bush chisel or hammer having the head provided with a socket in the lower face thereof and the integral lugs projecting from the ends of the side walls of said socket, the gib-plate in the bottom of said socket between said side walls, the cut- I In testimony whereof I have hereunto set tor-plates in and filling said socket, having I my hand in presence of two subscribing wittheir inner ends abutting against the gibnesses.

plate and provided in their outer edges with JOHN CAMPBELL. 5 coincident notches, and the bolts in said Witnesses:

notches and extending through the lugs, sub- DAVn) LooKToN,

stantially as described. ELVIRA ADAMS. 

